using System;
using System.Collections.Generic;
using System.Linq;
using ConjureBivouac2012.GameStates;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
using ConjureBivouac2012.Object;
using ConjureBivouac2012.Mathematics;
using ConjureBivouac2012.World;

namespace ConjureBivouac2012
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class GameManager : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;

        IGlobalGameState currentState = null;
  
        private enum AppType {prez, debug, demo}

        public bool ExitActive;

        // CONSTRUCTOR
        public GameManager()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";

            //graphics.IsFullScreen = true;

            //graphics.PreferredBackBufferWidth = 1280;
            //graphics.PreferredBackBufferHeight = 768;

            graphics.PreferredBackBufferWidth = 800;
            graphics.PreferredBackBufferHeight = 600;

            ExitActive = false;
        }

        public IGlobalGameState GetCurrentState()
        {
            return currentState;
        }

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here

            SetState(new MainMenu(Content, GraphicsDevice));
            base.Initialize();
        }

        public void SetState(IGlobalGameState newState)
        {
            if (currentState != null)
            {
                if (newState != currentState)
                {
                    currentState.Exit();
                }
            }

            currentState = newState;
            currentState.Enter();
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);



            // TODO: use this.Content to load your game content here
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (ExitActive && (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape)))
                this.Exit();

            if (Keyboard.GetState().IsKeyDown(Keys.F1))
                this.SetState(new MainMenu(Content, GraphicsDevice));

            // TODO: Add your update logic here);
            if (currentState != null)
            {
                currentState.Execute(gameTime);
            }

            base.Update(gameTime);

        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.Black);

            spriteBatch.Begin(SpriteSortMode.BackToFront,
                               BlendState.AlphaBlend, SamplerState.LinearWrap, null, null, null);

            // TODO: Add your drawing code here
            if (currentState != null)
            {
                currentState.Draw(spriteBatch);
            }
           
            spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}
